Y2O3 nanocrystallite has been successfully synthesized by sol-gel technique. Y(NO3)3.4H2O and TEOS were used as precursors and obtained powdered form of the oxide. In this study, stepwise annealing process has been performed and obtained almost spherical Y2O3 nanocrystallites. As-prepared sample was annealed at 900°C and their comparison has been studied in detail. Structural investigations of the prepared nanocrystallites were carried out by XRD and TEM. Optical behavior of the sample was investigated using UV-Vis absorption spectra. Also, band gap energy Eg = 5.9 eV has been calculated using Tauc’s plot. It is expected that the studies of these phenomena would open a new vistas of energy conversion devices and high speed optoelectronic instrumentation. Copyright © 2017 VBRI Press.